My two girls were 15 months apart and so pretty much wanted what ever the other had. I found several things that were very effective, first my solution was to let them each have the toy for five minutes at a time. They thought this was ridiculous and found a way to work it out minus me--great! Second, I found a wonderful book called The Egg Book by C Aschenbrenner. It is an Easter egg hunt in a book. One of them would hide the eggs and the other would find them. They needed each other to continue the game. Check it out at lewisandclarkpress.com.